Víctor Villagrá

Dr. Víctor Villagrá

Universidad Politécnica de Madrid (UPM)
orcid

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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12 September 2017 in IEEE Transactions on Dependable and Secure Computing
Verified
Journal Article
Closed access
PHPilar Holgado
Pilar Holgado
Víctor VillagráVíctor Villagrá
Víctor Villagrá
LVLuis Vazquez
Luis Vazquez
A novel method based on the Hidden Markov Model is proposed to predict multistep attacks using IDS alerts. We consider the hidden states as similar phases of a particular type of attack. As a result, it can be easily adapted to multistep attacks and foresee the next steps of an attacker. To achieve this goal, a preliminary off-line training phase based on observations will be required. These observations are obtained by matching the IDS alert information with a database previously built for this purpose using a clusterization method from the CVE global database to avoid overfitting. The training model is performed using both unsupervised and supervised algorithms. Once the training is completed and probability matrices are computed, the prediction module compute the best state sequence based on the state probability for each step of the multistep attack in progress using the Viterbi and forward-backward algorithms. The training model includes the mean number of alerts and the number of alerts in progress to assist in obtaining the final attack probability. The model is analyzed for DDoS phases because it is a great problem in all Internet services. The proposed method is validated into a virtual DDoS scenario using current vulnerabilities. The results proving the system's ability to perform real-time prediction.

19 January 2021 in Sensors
Verified
Journal Article
Open access
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XLXavier A Larriva-Novo
Xavier A Larriva-Novo
Víctor VillagráVíctor Villagrá
Víctor Villagrá
Mario Vega-BarbasMario Vega-Barbas
Mario Vega-Barbas
Diego RiveraDiego Rivera
Diego Rivera
MRMario Sanz Rodrigo
Mario Sanz Rodrigo
Security in IoT networks is currently mandatory, due to the high amount of data that has to be handled. These systems are vulnerable to several cybersecurity attacks, which are increasing in number and sophistication. Due to this reason, new intrusion detection techniques have to be developed, being as accurate as possible for these scenarios. Intrusion detection systems based on machine learning algorithms have already shown a high performance in terms of accuracy. This research proposes the study and evaluation of several preprocessing techniques based on traffic categorization for a machine learning neural network algorithm. This research uses for its evaluation two benchmark datasets, namely UGR16 and the UNSW-NB15, and one of the most used datasets, KDD99. The preprocessing techniques were evaluated in accordance with scalar and normalization functions. All of these preprocessing models were applied through different sets of characteristics based on a categorization composed by four groups of features: basic connection features, content characteristics, statistical characteristics and finally, a group which is composed by traffic-based features and connection direction-based traffic characteristics. The objective of this research is to evaluate this categorization by using various data preprocessing techniques to obtain the most accurate model. Our proposal shows that, by applying the categorization of network traffic and several preprocessing techniques, the accuracy can be enhanced by up to 45%. The preprocessing of a specific group of characteristics allows for greater accuracy, allowing the machine learning algorithm to correctly classify these parameters related to possible attacks.

8 December 2017 in Sensors
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Journal Article
Open access
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Manuel Alvarez-CampanaManuel Alvarez-Campana
Manuel Alvarez-Campana
GLGregorio Lopez
Gregorio Lopez
EVEnrique Vázquez
Enrique Vázquez
Víctor VillagráVíctor Villagrá
Víctor Villagrá
FBFundetel Berrocal
Fundetel Berrocal
Internet of Things platforms for Smart Cities are technologically complex and deploying them at large scale involves high costs and risks. Therefore, pilot schemes that allow validating proof of concepts, experimenting with different technologies and services, and fine-tuning them before migrating them to actual scenarios, are especially important in this context. The IoT platform deployed across the engineering schools of the Universidad Politécnica de Madrid in the Moncloa Campus of International Excellence represents a good example of a test bench for experimentation with Smart City services. This paper presents the main features of this platform, putting special emphasis on the technological challenges faced and on the solutions adopted, as well as on the functionality, services and potential that the platform offers.

9 November 2017 in IEEE Systems Journal
Verified
Journal Article
Closed access
WFWenjun Fan
Wenjun Fan
Zhihui DuZhihui Du
Zhihui Du
DFDavid Fernandez
David Fernandez
Víctor VillagráVíctor Villagrá
Víctor Villagrá
A honeypot is a type of security facility deliberately created to be probed, attacked, and compromised. It is often used for protecting production systems by detecting and deflecting unauthorized accesses. It is also useful for investigating the behavior of attackers, and in particular, unknown attacks. For the past 17 years plenty of effort has been invested in the research and development of honeypot techniques, and they have evolved to be an increasingly powerful means of defending against the creations of the blackhat community. In this paper, by studying a wide set of honeypots, the two essential elements of honeypots—the decoy and the captor—are captured and presented, together with two abstract organizational forms—independent and cooperative—where these two elements can be integrated. A novel decoy and captor (D-C) based taxonomy is proposed for the purpose of studying and classifying the various honeypot techniques. An extensive set of independent and cooperative honeypot projects and research that cover these techniques is surveyed under the taxonomy framework. Furthermore, two subsets of features from the taxonomy are identified, which can greatly influence the honeypot performances. These two subsets of features are applied to a number of typical independent and cooperative honeypots separately in order to validate the taxonomy and predict the honeypot development trends.

26 July 2004 in IEEE Communications Magazine
Verified
Journal Article
Closed access
JVJorge E. Lopez de Vergara
Jorge E. Lopez de Vergara
Víctor VillagráVíctor Villagrá
Víctor Villagrá
FBFundetel Berrocal
Fundetel Berrocal
The extended markup language (XML) has emerged in the Internet world as a standard representation format, which can be useful to describe and transmit management information. However, XML formats alone do not give formal semantics to it. To solve this question, ontology languages based on the resource description framework can be used to improve the expressiveness of management information specifications. This article presents an approach that uses an XML-based ontology language to define network and system management information. For this, the structures of the Web ontology language known as OWL are analyzed and compared to those used in management definitions, also studying the advantages ontology languages can provide in this area.

8 April 2019 in International Journal of Information Security
Verified
Journal Article
Closed access
PDF file
RRRaul Riesco
Raul Riesco
Víctor VillagráVíctor Villagrá
Víctor Villagrá